This study determined whether increased fluid intake in normal healthy volunteers produces any significant change in stool volume or frenquency and if so, to determine the magnitude of the increase in daily fluid intake needed to do so. After a 72-hour baseline diet and stool collection, the subjects ingested increasing amounts of Gatorade or water in addition to their baseline fluid and food intake. Data regarding the stool volume, weight and frequency were collected and analyzed. Progressive increase of oral intake of fluid to 2000 cc above baseline did not alter fecal output. These results sugget that 1) the gut has considerable reserve absorptive capacity, and 2) recommendations for increased fluids in constipated individuals may not have the expected results.